As a background art relating to the present technology is already known the following Patent Document 1, for example, and in that publication, for the purpose of “providing a mobile unit determining system and a mobile unit determination method, for enabling to determine a mobile unit approaching thereto, on a road having a low visibility, such as, a dead angle of crossroads or a curve having bad view, etc, and further a computer program for achieving said mobile unit determination method with using a computer therein,” and as a means for dissolving that, there is disclosed a technology “A CPU 28 calculates an averaged value of motion vector directions of pixels within linked blocks, and identifies the averaged value calculated as a direction of movements of the linked blocks. The CPU 28 calculates a difference of angle between the identified direction of movement and a predetermined approaching direction, and if the calculated difference of the angle is equal to or less than a second threshold value, it produces a display image to be composed with a photographed image. With doing this, the display information for emphasizing that mobile unit is added, when it is determined that there is a mobile unit moving in a direction approaching thereto, as being the mobile units on the photographed image.”